What can I do to help an addict in my life?

Be supportive but not an enabler. Supportive as in helping them make a positive change in their lives, this could include making changes in the helper's life. Enabling is anything that makes it easier for the person to continue with their addiction, like loaning them money. Let them know about resources without trying to force the issue. Preaching, coercion, bribing, yelling are usually not effective ways to achieve a lasting change.

The addict has to be willing to accept your help. This needs to be managed by a professional depending on the addiction but it is a tremendous benefit to the addict to have a support system.